Back Pain That Travels Down One Leg

Back pain that travels into a leg is frightening in a way that back pain alone is not.

It feels like it is spreading. It feels like something is being squeezed. And because the pain is in a place you cannot explain by anything you did, people assume it means something serious is happening.

Usually it does not. But it does need a proper examination first, and it needs explaining properly, which is what this guide is for.

One thing before you start. This guide assumes I have examined you, checked your nerves, and found none of the warning signs in section 15. That check is the reason the rest of this applies to you. If nobody has examined you yet, read section 15 first.

The short version

• Your pain is real. Everything below assumes that.
• Pain in one leg is much better news than pain in both. I will explain why in section 6.
• You have none of the emergency warning signs. I checked specifically. That was the most important part of your examination.
• Pain is an alarm, not a damage meter.
• There are two things that can send pain down a leg, and one of them is far less serious than people assume.
• Discs shrink on their own, and the worst looking ones shrink the most.
• Scans find wear in almost everyone, including people with no pain at all.
• Recovery is usually slower than people want and better than they fear. I will give you the honest numbers.
• What you believe about your recovery affects your recovery. That is not motivational talk. It came out of the research.

1. Where your pain is coming from

Your pain sits across the lower back, around the level where the ribs end and the lower back begins, and it travels down one leg.

There are two different things that can produce that, and they are often confused.

The first is what most people mean by sciatica. A nerve root low in the lumbar spine gets irritated or compressed, usually by disc material. That nerve runs into the leg, so the leg complains.

The second is referred pain from the area itself. When joints, muscles and ligaments in the back are irritated, they produce a spreading ache that can travel a surprising distance into the buttock, the hip and the thigh, without any nerve being compressed at all. Doctors call this somatic referred pain.

They can feel similar to you and they are quite different underneath. Telling them apart is a large part of what the examination was for, and it changes what we do.

Sections 4 and 5 take each one in turn.

2. Pain is an alarm, not a damage meter

Most people think of pain like a fuel gauge. More pain means more damage.

That is not how it works, and knowing this changes things.

Pain is produced by your brain. It is an alarm system, and its job is protection, not measurement. Your brain takes the signals coming in from the tissues and weighs them against everything else it knows. How tired you are. How worried you are. What happened last time. What you think this means.

Then it decides how loud to make the alarm.

This matters more than usual with leg pain, because leg pain is alarming in itself. An area that has never hurt before suddenly does, and your brain has learned that this is important information. So the volume goes up, which makes it feel more serious, which turns the volume up again.

Severe pain here is genuinely common and does not mean severe damage.

3. The pain gate

In 1965, two researchers called Melzack and Wall described something that still explains more than almost anything else in pain science.

There is a gate in your spinal cord. Signals from the body pass through it before reaching the brain. It can open wider, letting more through, or close, letting less through.

Movement and touch close it. Signals from moving joints and working muscles travel on faster nerve fibres than pain signals. They get there first and crowd the gate.

This is why gentle movement usually eases things more than lying still does, and why a hot water bottle helps.

Stress, poor sleep and worry open it. None of those are your fault, and all of them are worth attention.

4. What sciatic referral actually means

The word sciatica gets used for any pain down a leg. Properly, it means pain arising from irritation of a nerve root in the lower back.

Here is what people are rarely told: in most cases the nerve is irritated and inflamed, not crushed.

Disc material pressing against a nerve root triggers a chemical inflammatory reaction. It is the inflammation that produces most of the pain, not the pressure. This is why the pain can be severe while the nerve itself continues to work perfectly well, and why it can settle substantially before anything has changed on a scan.

Nerve pain has its own character. Burning, electric, hot, shooting. It often travels in a stripe rather than a patch. It can come with pins and needles or numbness.

Pins and needles and numbness are not signs of nerve damage. They are signs of a nerve that is being disturbed. Disturbed nerves settle.

5. The thoracolumbar junction, the one nobody mentions

This is worth its own section, because it is the part most people have never had explained. The junction where your ribs end and your lower back begins is a busy place. It is the point where a stiff, rib-supported section of spine meets a mobile one, and it takes a lot of rotational load.

Nerves from this level do something surprising. Small nerves branch off around T12 and L1, then travel downwards and outwards, crossing over the top of the pelvis to supply the skin of the upper buttock. They are called the superior cluneal nerves.

Which means irritation at the level of your lowest ribs can produce pain over your hip and into your buttock, a long way from where the problem actually is. When it does, it can look and feel very much like sciatica. Researchers have gone as far as calling it pseudo-sciatica.

How common is it? A prospective study of 834 people with low back pain or leg symptoms found that 14 in 100 met the criteria for this, and that about half of those also had leg symptoms. Other studies put the figure lower, from under 2 in 100 upwards.

I want to be honest about the strength of this. The range between studies is wide, the condition is defined differently by different researchers, and it is not something every clinician looks for. So treat this as a real possibility worth knowing about, not as a confirmed diagnosis.

Why it is worth telling you anyway. If some of your leg pain is coming from this rather than from a compressed nerve root deep in your spine, that is a far less worrying source, and it responds well to treatment of the area it actually comes from. It is one of the reasons the examination looked at your lowest ribs and the top of your pelvis, when your complaint was about your leg.

6. Why one leg is good news, and what I checked for

This section is short and it is the one to remember.

Your pain is in one leg. That is genuinely reassuring.

Pain and numbness down both legs at once, or spreading from one leg to the other, is one of the signals that something is pressing centrally in the spinal canal rather than on a single nerve root. You do not have that.

I also checked for the other signals, and you do not have those either:

• Any change in feeling between the legs, around the back passage or genitals
• Any change in bladder or bowel control, or in the sensation of needing to go
• Weakness that is worsening, or legs that give way
• Numbness that is spreading rather than staying in one place Together, these are what we screen for to rule out a condition called cauda equina syndrome. It is rare, it is an emergency when it happens, and it is the single most important thing to exclude in someone with back and leg pain. Your examination did not show it.

I am telling you this in detail deliberately. Not to frighten you, but because knowing exactly what was checked and exactly what was found is usually more reassuring than being told not to worry. Section 15 lists the same signs, so you know what would change things.

7. What the scans show

Researchers scanned thousands of people who had no back pain at all. Then they counted what turned up.

• At 40, about 7 in 10 had disc wear, and half had a disc bulge.
• At 50, about 8 in 10 had disc wear, and 6 in 10 had a bulge.
• At 60, nearly 9 in 10 had disc wear, and 7 in 10 had a bulge.

Not one of those people had any back pain.

These findings are like grey hair. Very common, increasing with age, and on their own they tell you little about who hurts.

Scans matter more when there is leg pain than when there is not, because if surgery or an injection ever became a question, we would need to know exactly which level is involved. But they are still poor at explaining pain, and the words on the report do harm of their own. Degeneration. Bulge. Wear. Frightening words raise threat, threat opens the gate, and people who believe their spine is crumbling move less and guard more.

Scans earn their place when something specific is suspected that would change the plan. Not for reassurance, because they are bad at providing it.

8. The best news in this guide: discs shrink

This is the section worth reading twice.

Researchers gathered the studies that scanned people with disc herniations, then scanned them again later. The discs shrink on their own. And the pattern is the opposite of what anyone expects.

• The worse the herniation looks, the more likely it is to shrink.
• A sequestration, where a fragment has broken off completely and the worst kind on paper: 96 in 100 shrank. In 43 in 100 it disappeared entirely.
• An extrusion, where material has squeezed out through the outer ring: 70 in 100 shrank.
• A protrusion, a smaller bulge: 41 in 100 shrank.
• A simple bulge: 13 in 100 shrank.

Read that again. The most alarming word on your scan report is attached to the best odds.

The reason makes sense once you hear it. When disc material escapes and meets your blood supply, your body treats it as something that does not belong there and clears it away. The more material that escapes, the more your body has to work with. A tight little bulge that never breaks through stays put. A dramatic escaped fragment gets mopped up.

9. What recovery actually looks like

I am going to give you the honest numbers rather than the comfortable ones.

A UK study followed 609 people who came to their GP with back and leg pain. At twelve months, 55 in 100 had improved.

That is just over half, and it is lower than most people expect. I would rather you heard it from me than discovered it yourself later and wondered what else I had softened.

Here is what I take from it.

First, "improved" is a strict measure. It is not the same as "still has some symptoms". Plenty of the rest were better than they started without crossing the line the researchers drew.

Second, and this is the part that matters most, the study found what predicted a worse outcome. Three things stood out: having had the symptoms longer before seeking help, how much the pain had become part of how the person saw themselves, and what the person believed about how long their recovery would take.

Read that last one again. Believing recovery will be long and difficult was itself associated with a worse outcome. That is not a reason to pretend to be positive. It is a reason to make sure what you believe is accurate rather than frightening, which is the entire purpose of this document.

A few practical things about the shape of recovery:

• It is rarely a straight line. Good days and bad days in no obvious order is normal.
• The pain usually settles before the numbness does. Tingling and numbness can linger for months after the pain has gone. Expected, and not a bad sign.
• Leg pain often eases before back pain. Many people find the leg quietens and they are left with a sore back, which feels like going backwards. It is the opposite.
• The first few weeks are usually the worst.

10. Moving is safe, and finding what eases it

The instinct is to rest until it settles. Bed rest makes back pain worse and makes it last longer. That is well settled.

But this is not a case of "just keep moving". With leg pain, direction matters.

Find your easing position and use it deliberately. Most people with this have one. For some it is lying on the back with knees bent. For some it is lying on the good side with a pillow between the knees. For some it is standing and walking. For some it is leaning forward onto a worktop.

Whatever yours is, it is not cheating and it is not avoidance. It is the position that takes tension off an irritated nerve, and using it several times a day is a legitimate part of getting through this. Tell me what it is. It is one of the most useful pieces of information you can give me.

Alongside that:

• Keep moving between the rests. Little and often.
• Walk if walking helps. Many people find it does. Some find it does not, in which case do not force it yet.
• Judge it by tomorrow. More ache during or just after is fine. The question is whether you are back to your usual baseline within about a day.
• Watch the direction of travel, not the level. Pain moving out of the leg and back towards the spine is progress, even if the back pain gets louder for a while. Pain moving further down the leg is worth telling me about.

11. Sitting, driving and sleeping

These three cause more trouble than anything else with this problem.

Sitting usually loads an irritated lumbar nerve more than standing does. Get up every twenty to thirty minutes. A rolled towel in the small of your back helps some people. A higher seat is usually easier than a low soft one. Driving is sitting plus vibration plus a fixed position, which is why it is often the worst thing of all. Break long journeys. Move the seat back and raise it if you can. Do not power through a two hour drive to prove something.

Sleeping. On your back, a pillow under the knees. On your side, a pillow between the knees, and lie on whichever side is more comfortable. There is no rule about which side.

If the nights are bad, say so. Poor sleep makes tomorrow hurt more, reliably, and there are things worth trying before you spend another fortnight awake.

12. A word about painkillers

UK guidance on sciatica is firmer and more specific than most people expect, and it surprises people.

• Gabapentin and pregabalin are specifically not recommended for sciatica. Nor are other anti-epileptic medicines, oral steroids, or diazepam and similar. The guidance is clear on this: the evidence of benefit was lacking and the harms were documented.
• Opioids are not recommended for long standing sciatica.
• Anti-inflammatory tablets have limited evidence of benefit here and known risks. If used, it should be at the lowest dose that helps, for the shortest time.
• Paracetamol alone is not recommended for back pain.

If you are already on any of these, do not stop suddenly. Some of them need to be reduced gradually, and that is a conversation with your GP rather than a decision to make on your own.

Anti-inflammatories are not free. If you have stomach trouble, kidney problems, high blood pressure, asthma, or take anything for your heart, ask your pharmacist first. No appointment needed.

Timing beats dose. Use pain relief to unlock movement or sleep. Painkillers that let you move are doing a job.

13. Pacing and flare-ups

The boom and bust pattern: a good day arrives, you feel nearly normal, so you do everything you have been putting off. You pay for three days.

Each cycle teaches your nervous system that activity is dangerous. It was the size of the jump.

Pacing means deciding in advance, not by feel. On a good day, do the planned amount and stop. When a flare comes:

• Go back to your easing position and use it more often, rather than stopping everything.
• Keep moving, smaller.
• Do not hunt for what you did wrong. Often there is nothing.
• Expect days to a couple of weeks.
• Tell me if the pain has moved further down the leg, or if anything has changed about strength or numbness. Those are the changes worth knowing about. A louder version of the same pain usually is not.

14. What treatment does, and what it does not

I would rather be straight with you.

What hands-on treatment and exercise can offer here:

• Reducing the muscle guarding that builds up around a painful back, which is hard to release on your own
• Restoring movement to areas that have stiffened up in protection, including the thoracolumbar junction in section 5
• Helping you find and use the positions and movements that ease your leg
• Giving your nervous system clear evidence that the area can be moved without disaster
• Keeping you moving and working while your body does the slower job underneath

What it does not do:

• It does not put a disc back in. Nothing is out of place.
• It does not remove a herniation. Your body does that, in its own time, as in section 8.
• It is not a course you complete and then you are fixed.

Treatment supports the process. It does not replace it. The recovery in section 8 happens on your body's timescale, and my job is to make that period more bearable and more active, and to spot promptly if anything changes.

You should expect me to be clear about what I am treating, to change the plan if it is not working, and to tell you plainly if you need a scan, your GP, or a specialist opinion.

15. When to get urgent help

Most back and leg pain is not an emergency. A few things are.

Go straight to A&E, or call 999

Do not wait to see if these settle. If you are offered a routine appointment, say you are worried about cauda equina syndrome and ask to be seen today. Do not contact the clinic first.

• Numbness or a changed feeling between your legs, around your back passage or genitals. Including toilet paper feeling different when you wipe.
• Trouble starting to wee. Not being able to feel it coming out. Losing the feeling of a full bladder. Any new loss of control of your bladder or bowels.
• New numbness during sex, or new trouble getting an erection.
• Pain or numbness down both legs at once, or pain that has spread from one leg to the other.
• New or quickly worsening weakness in one or both legs, or your legs giving way.
• Sudden severe pain in your back or tummy with faintness, a cold sweat, or a throbbing feeling in your tummy.
• Severe pain straight after a bad fall or accident.

Contact your GP or NHS 111 today

• Weakness that is getting worse, especially if your foot is starting to drag or catch, or you cannot lift the front of your foot properly.
• Sudden severe back pain after a minor fall, a bump, a cough or a sneeze, or with no cause at all. Especially with osteoporosis, long term steroid use, or a previous broken bone from a minor injury. This can be a spinal fracture.
• Back pain with a fever, shivering, or feeling generally unwell.
• Back pain with weight loss you cannot explain, night sweats, or a past history of any cancer.
• Pain that is much worse at night, wakes you every night, and is not eased by any change of position.

Worth telling me at your next appointment

• Where the pain is now compared with last time. Moving up out of the leg is good. Moving further down is worth knowing.
• Your easing position, if you have found one.
• Anything new about strength or numbness.

Everything else, including a bad flare-up, can wait for a normal appointment.

16. If you want to read or watch more

Start here

• Tame the Beast. A five minute animation by Professor Lorimer Moseley. The best possible starting point. tamethebeast.org
• Flippin' Pain. A UK campaign about long lasting pain. flippinpain.co.uk
• NHS advice on sciatica. nhs.uk/conditions/sciatica

Practical help

• The Pain Toolkit, by Pete Moore. Very good on pacing and boom and bust. paintoolkit.org
• Recovery Strategies, by Greg Lehman. A free illustrated workbook. greglehman.ca/recovery-strategies-pain-guidebook

The research behind this guide

• Melzack R, Wall PD. Pain mechanisms: a new theory. Science, 1965. The original pain gate paper.
• Kuniya H et al. Prospective study of superior cluneal nerve disorder as a potential cause of low back pain and leg symptoms. Journal of Orthopaedic Surgery and Research, 2014. The figures in section 5.
• Brinjikji W et al. Imaging features of spinal degeneration in asymptomatic populations. American Journal of Neuroradiology, 2015. The scan figures in section 7.
• Chiu CC et al. The probability of spontaneous regression of lumbar herniated disc: a systematic review. Clinical Rehabilitation, 2015. The shrinkage figures in section 8.
• Konstantinou K et al. Prognosis of sciatica and back-related leg pain in primary care: the ATLAS cohort. The Spine Journal, 2018. The recovery figures and prognostic factors in section 9.
• NICE guideline NG59. Low back pain and sciatica in over 16s, updated 2026. The medication advice in section 12 comes from recommendations 1.2.16 and 1.2.17.

Bring any of this to your next appointment. Especially the parts that did not sit right, or that felt uncomfortably familiar.

This guide is general information. It does not replace the advice I give you in clinic.